1. Field of the Invention
This invention relates to highly-oxidized pitch fibers having a high degree of flexibility and handleability which can be easily processed to produce carbon or graphite fibers, or woven or knit to produce a fabric which in turn may be heat treated to produce a carbon or graphite cloth.
2. Description of the Prior Art
The production of carbon and graphite fibers from pitch is well known in the art. Such fibers are usually produced by spinning a fiber from the pitch, thermosetting the fiber so produced by heating the fiber in an oxygen-containing atmosphere for a time sufficient to render it infusible, and then heating the infusible fiber to a carbonizing or graphitizing temperature in an inert atmosphere. While the carbonized or graphitized fibers produced in this manner are characterized by high strength, the as-spun and oxidized fibers have a very low strength. For this reason, such fibers are difficult to work with and considerable care must be exercised in processing such fibers to carbon and graphite to avoid breakage of the fibers.
Because of the low strength of the as-spun and oxidized fibers, it is customary to first carbonize or graphitize such fibers in order to improve their strength before attempting to weave or knit them into a cloth. However, while the carbonized and graphitized fibers have high strength, they also are characterized by high modulus which makes them difficult to work with because of their brittleness.